Method of charging small caliber high explosive shells



Oct. 23, 1934. H. SCHULER 1,978,146

METHOD OF CHARGING SMALL CALIBER HIGH EXPLOSIVE SHELLS Filed Jan. 19,1934 Patented Oct. 23, 1934 METHOD 0F CHARGING SMALL CALIBER HIGH'EXPLOSIVE SHELLS Hermann Schiller, Dusseldorf, Germany, assignor toRheinische Metallwaarenund Maschinenfabrick, Dusseldorf-Derendorf,Germany Application January 19, 1934, Serial No. 707,389

In Germany November 6, 1933 3 Claims.

Small caliber high explosive shells of the order of magnitude of 2 toabout 4 cm. caliber were formerly charged by inserting an explosivecharge in pulverulent form into the cavity of the projectile to befilled, the charge being then pressed firmly under a pressure of about3000 atm. By this method, however, the walls of the shell may besubjected to excessive strain and, particularly in the case ofarmour-piercing shells, fine cracks are produced in the interior of thepoint of the shell which is hollowed out ogive-wise, and these crackscause the projectile, on striking an armoured target, to becomeshattered. instead of piercing the armour.

There is another method of charging designed to overcome such drawbacks,according to which the explosive is prepared as a compressed body in aspecial matrix under high pressure, whereupon it is inserted with theapplication of slight pressure in the cavity of the projectile linedwith a layer of paraffin or wax. The soft intermediate layer compensatesfor constructional inaccuracies in the dimensions of the cavity of theprojectile and in the explosive core. On the other hand, however, inconsequence of its low melting point it melts, when the gun is fired, bythe heating of the body of the shell and by the passage of theprojectile through the barrel and the explosive core swims in a paste orliquid mass. The paraffin, wax or the like may then settle between thefuze and its detonator, thus rendering explosion impossible. Blinds mayresult on this account and particularly by use of paramn for thereasonthat, on the generation of intense heat when the shell strikes a hardtarget, the paraffin suddenly evaporates, producing a high pressurewhich blows the fuse from the body of the projectile before it has hadan opportunity to ignite the charge.

These drawbacks are avoided of the method according to the invention.

According to this method the explosive charge is first of all preparedas a compressed body in a matrix under high pressure, the diameter ofthesaid body being less than that of the cavity in the projectile to befilled, but having a somewhat greater length. The body is then, withoutthe use of any intermediate linings, pressed at a pressure of about400-atm. into the body of the projectile after being heated with it toabout 50-60. In order that the explosive core may be firmly fixed in thelongitudinal direction of the projectile distance pieces, which may bein the form of cardboard discs with brass covers, are preferablyintroduced between the core and. the oppositely disposed end surface ofthe locking screw.

The drawing shows a section of an armourpiercing high explosive shellwith base fuze charged by the method according to the invention.

a is the explosive core pressed in a matrix of a smaller diameter thanthe central bore of the projectile and of greater length, at a pressureof about 3000 atm., the length of the core before being pressed into thebore of the projectile being greater than the length :B. After theexplosive core a has been thrust loosely into the bore of theprojectile, the projectile and the explosive core are heated to about5060, and the said core a is compressed at about 400 atm., whereby it iscaused to bear tightly against the walls of the projectile. After thedetonator b has been inserted, in order to compensate for the spacebetween the bottom of the explosive core a and the base fuze screw 0,there is inserted a suitable number of thin, perforated cardboard discs(1 and a brass closing disc e, which is pressed tightly against theexplosive core a by the base fuze screw 0, a space y being allowed forstill further pressure to be exerted by the screw 0 on the discs andthus the firm positioning of the explosive core is ensured.

I claim 1. A method of charging high explosive shells which comprisesthe steps of molding the explosive charge in a matrix under highpressure to a compressed body having a diameter smaller than thediameter of the cavity of the shell to be filled and somewhat longerthan the length of the cavity to be filled, heating the shell and thecharge body and pressing the charge body into the cavity of the shellwhereby the explosive body bears tightly against the sides of the cavityof the shell, and closing the end of the cavity.

2. A method according to claim 1, in which the temperature of theheating step ranges between 50-60 C. and the pressure of the pressingstep approximates 400 atm.

3. A method of charging high explosive shells which comprises the stepsof molding the explosive charge in a matrix under high pressure to acompressed body having a diameter smaller than the diameter of thecavity of the shell to be filled and somewhat longer than the length ofthe cavity to be filled, pressing the charge body into the cavity of theshell to be filled to force the explosive body tightly against the sidesof the cavity of the shell, and closing the end of the cavity.

HERMANN SCHULER.

